Loop Collection and Update documents in MongoDB

mongo_script

var collection = db.getCollection('collectionName');
var bulkOp = collection.initializeOrderedBulkOp();
var count = 0;
collection.find().forEach(function(doc) {
  bulkOp.find({ '_id': doc._id }).updateOne({
    '$set': { 'email': doc.email.replace('what to replace', 'replace with') }
  });
  count++;
  if(count % 100 === 0) {
    // Execute per 100 operations and re-init
    bulkOp.execute();
    bulkOp = collection.initializeOrderedBulkOp();
  }
});

// Clean up queues
if(count > 0) {
  bulkOp.execute();
}


// Reference and Credit
// https://stackoverflow.com/a/8588031/1184418